An embodiment relates to leakage measurement for batteries.
Electric vehicles utilize use one or more electric motors or what is known as traction motors for propulsion. One form of electric vehicle includes plug-in electric vehicle (PEV) which utilizes rechargeable battery packs that can be charged from an electric grid, and the electricity stored onboard drives or contributes to drive the wheels for propulsion. The rechargeable battery packs are often connected in series for supplying a high voltage energy supply to meet the vehicle's operating requirements.
The battery voltages are monitored for identifying the battery's state-of-charge, determining an end-of-life so the battery can be replaced prior to failure, and for determining whether a short exists in the high-voltage system or whether any small leakage currents exists for identifying unknown battery drain.
Current systems that monitor electrical leakage from the battery are either complex and/or costly, using numerous switches on each battery cell within a battery cell string to identify a leakage. Therefore, a system that provides the advantages of identifying current leakage utilizing a low-cost and less complex detection circuit is needed.